Change: Support custom transparency remaps with 32bpp blitters.

This closes a 15 year old TODO...

Codechange: Replace pointer to Sprite array with reference to SpriteCollection. (#11580)

Add `SpriteLoader::SpriteCollection` type which is an array of `SpriteLoad::Sprite`.

This removes the ambiguity of what `SpriteLoader::Sprite *` is pointing to,
and cleans up mismatches using both dereference -> and array access [] for the
same object.

Codechange: automatic adding of _t to (u)int types, and WChar to char32_t

for i in `find src -type f|grep -v 3rdparty/fmt|grep -v 3rdparty/catch2|grep -v 3rdparty/opengl|grep -v stdafx.h`; do sed 's/uint16& /uint16 \&/g;s/int8\([ >*),;[]\)/int8_t\1/g;s/int16\([ >*),;[]\)/int16_t\1/g;s/int32\([ >*),;[]\)/int32_t\1/g;s/int64\([ >*),;[]\)/int64_t\1/g;s/ uint32(/ uint32_t(/g;s/_uint8_t/_uint8/;s/Uint8_t/Uint8/;s/ft_int64_t/ft_int64/g;s/uint64$/uint64_t/;s/WChar/char32_t/g;s/char32_t char32_t/char32_t WChar/' -i $i; done

(svn r11076) -Fix: MakeTransparent of 32bpp blitter used 0..100; using 0..255 makes it much faster (frosch)
-Fix: ComposeColourXXX could work a tiny bit faster when using 256, not 255 as value to divide with; downside is that it can give alpha errors (frosch)

(svn r10190) -Codechange: merged renderer and blitter to one single class API: blitter
-Codechange: introduced a hierachy of blitters to avoid a lot of code duplication
Note: this allows much easier adding other types of video-drivers, like OpenGL

(svn r10132) -Codechange: split out the last direct video-buffer read access to the blitter-layer
-Add: added a new renderer and blitter to make room for some optimized bpp
-Fix: fill the alpha channel in the grf-spriteloader